1. Field of the Invention
The present invention is directed to an intracavitary ultrasound probe for producing tomograms of an examination region, of the type having a section adapted for introduction into a body cavity, the section having a distal end with an endpiece which contains a convex transducer array.
2. Description of the Prior Art
European Application 0 446 645 discloses an intracavitary ultrasound probe of the type described above for prostate examinations. The prostate probe permits scanning the prostate with ultrasound beams proceeding from the rectum, and to produce tomograms of the prostate from the echo signals. This known ultrasound probe has a straight introduction section terminating in a distal end with a curved endpiece. The curved endpiece has an outer surface which is convexly shaped, and in which a convex transducer array is disposed. The transducer elements of the convex transducer array are activated from group-to-group in order to conduct a sector scan. The advantage of such a convex transducer array is that the ultrasound tomograms produced therewith exhibit a good graphic resolution of details in the near range of the transducer array. Moreover, convex transducer arrays offer a large scan field, so that tomograms of the entire prostate can be produced.
It would also be desirable for diagnostic and/or therapeutic purposes if the examination region could be displayed in not just one plane of section, but in a plurality of planes of section which have a common origin. A presentation of the examination region in two planes of section disposed perpendicularly relative to each other would be especially useful.
Another intracavitary ultrasound probe is disclosed in U.S. Pat. No. 4,543,960. This ultrasound probe is a transesophagal probe for cardiac examinations. The scan head of this known probe includes an interior chamber in which a phased array is rotatably mounted, in order to be able to scan in different planes. The array is rotated in the plane of the transducer elements which form the array. In the near range of the array, however, the resolution of the phased array is low, so that anatomical details in the immediate proximity of the scan head are inadequately imaged.